On 15/08/2024 at 07:39, David Alexander Geister wrote:
I created the array with: sudo mdadm --create --verbose /dev/md0
--level=5 --raid-devices=3 /dev/sda /dev/sdb /dev/sdc
So you really used the whole unpartitioned disks as RAID members.
It looks like the disk has a GPT partition table. Is this expected ?
If not, it could be another instance of unintended GPT "recovery",
and a reason against using unpartitionned disks.
Yes I choose GPT intentional as each of the HDDs exceed 2TB
This makes no sense. A whole disk sdX must not be used as a RAID member
and have a partition table at the same time. Either the disk has no
partition table and is use as a RAID member, or it has a partition table
and a partition sdX1 is used as a RAID member.
Besides, the GPT primary partition table and the RAID 1.2 superblock use
the same location at the beginning of the disk.
Did you create the partition table before or after creating the RAID array ?
If you create a GPT partition table after creating the RAID array, the
primary partition table will overwrite the RAID superblock.
If you create a GPT partition table before creating the RAID array, the
RAID superblock overwrites the primary partition table, but not the
backup partition table located at the end of the disk. There have been
reports lately which seem to indicate that something, maybe the
BIOS/UEFI firmware, "restores" the primary partition table from an
existing backup partition table at boot.
> wipefs /dev/sda
DEVICE OFFSET TYPE UUID LABEL
sda 0x200 gpt
sda 0x74702555e00 gpt
sda 0x1fe PMBR
We can see that a primary and backup GPT partition tables are present.
If there are no important or unsaved data in the RAID array, I suggest
that you create a RAID partition sdX1 on each disk and create a new RAID
array using the partitions instead of the whole disks.
Otherwise, I suggest that you erase all GPT metadata on each disk with
wipefs -a before re-creating the RAID array with --assume-clean. When
re-creating the array, make sure that sda, sdb and sdc are in the same
physical order as when you originally created the RAID array (check with
the serial numbers).
